He told jurors he thought the Miami-Dade prosecutor was “the greatest” and a “pit bull.” Dressed in a snappy gray suit and sporting a trimmed beard, Montero said he was impressed with the advice of his standby public defense lawyer.

When Miami-Dade Judge Charlie Johnson pressed him Tuesday on whether he would testify or not, Montero stammered, then relented. “I’m just going to go ahead and rest. This is getting a little bit too complicated,” Montero said. “I didn't want to offend anybody.”

But jurors didn’t buy that his crime was as benign as his courtroom demeanor.

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A jury on Tuesday swiftly convicted Montero of sucker punching a South Beach bar manager — so hard that the man was left in a coma and suffered extreme brain injuries. The punch was captured on video surveillance, key evidence for prosecutors.

Montero now faces up to 30 years in prison as a designated “violent felony offender.”

Back in June, Montero had just gotten out of jail after prosecutors had to drop a carjacking charge against him. That night, he was harassing a woman at the Foxhole Bar, 1218 14th Ct., in Miami Beach.

The manager, Felipe Estevez, 38, eventually asked him to leave. A security guard escorted Montero out. The video showed the wiry, bald Montero pacing outside, angrily tussling with security while cursing and threatening to kill people.

“Is that Vin Diesel?” Montero asked during a pretrial hearing when shown the video of himself.

Montero suddenly cold-cocked Estevez in the temple. The man crumpled to the floor and was later hospitalized. In a coma for a week, Estevez was released only to be readmitted because of bleeding in the brain.

Estevez told jurors that today he struggles to articulate his words. For weeks, he slept while seated, vertigo keeping him from lying down. He said his vision remains blurry, and he constantly hears beeping in his hear, a permanent condition called tinnitus.

Montero, 38, refused the help of a lawyer, filing six different demands for a speedy trial. During jury selection, he asked no questions but introduced himself as having been “incarcerated for four months” and called prosecutor Denise Georges a “pit bull” whose questions “hit it on the head.”

He suggested to jurors that Estevez planned the fall in some kind of insurance scheme, or maybe was drunk. At one point, as the judge went over a jury instruction form with him, Montero said he realized that police officers never interviewed him before his arrest that night.